Cylinder head with two-plane water jacket

Abstract

A cylinder head for an engine having a two-plane water jacket in which a lower chamber at one plane through the head cools the fire deck of each cylinder and a cross-flow passage for the coolant is spaced above the lower chambers in a second plane through the head directs coolant to an outlet. The two planes of the water jacket are connected by an annular passage surrounding the injector nozzle sleeve and has machined surfaces whereby the size of the flow channel and thus the coolant flow between the two planes is better controlled to enable more even cooling of the fire deck resulting in less variability in fire deck temperature from one cylinder to one another. The lower chambers cooling the fire deck are separate for each cylinder to prevent heated coolant from one cylinder flowing to the next cylinder fire deck.

We claim:  
     
       1. A cylinder head for a multi-cylinder engine comprising a body having a lower wall defining a firing deck for each cylinder, the body having a hollow interior space forming a water jacket for cooling the cylinder head, the water jacket having, for each cylinder, a lower chamber adjacent the lower wall for cooling the firing deck, each lower chamber having at least one inlet for receiving coolant, an upper chamber spaced above the lower chamber and a channel extending between the lower and upper chambers, the water jacket further including a cross-flow passage in communication with each of the upper chambers for directing the coolant from each upper chamber to a coolant outlet whereby coolant flows into each lower chamber through the inlets thereof, through each channel to each upper chamber and from each upper chamber to the cross-flow passage and from there to the coolant outlet, wherein the channel is formed by a bore in the body and a fuel injector nozzle sleeve within the bore spaced inwardly from the surface of the bore whereby the channel is annular. 
     
     
       2. The cylinder head as defined by claim  1  wherein the lower chambers are separate from one another to prevent flow of coolant from one lower chamber to another without flowing through the channel and upper chamber of the associated cylinder and through the cross-flow passage. 
     
     
       3. The cylinder head as defined by claim  1  wherein adjacent lower chambers are coupled to one another by connecting passages permitting coolant flow between the adjacent lower chambers. 
     
     
       4. The cylinder head as defined by claim  1  wherein the channel is formed by a bore in the body with a machined surface. 
     
     
       5. The cylinder head as defined by claim  1  wherein the channel is located approximately in the center of the lower chamber and wherein the lower chamber has a plurality of inlets at radially outer locations relative to the channel whereby coolant flows inward from the inlets to the channel. 
     
     
       6. The cylinder head as defined by claim  5  wherein the lower chamber is generally rectangular in shape in a plan view with inlets in the four corners of the lower chamber. 
     
     
       7. A cylinder head for a multi-cylinder engine comprising a body having a lower wall defining a firing deck for each cylinder, the body having a hollow interior space forming a water jacket for coolant flow through the body, the water jacket having a lower chamber for each cylinder adjacent the lower wall, each lower chamber having at least one inlet for receiving coolant, the water jacket further having a cross-flow passage spaced from the lower chambers and terminating in a coolant outlet, the cross-flow passage being in fluid communication with each lower chamber to receive coolant via annular flow channels defined by bores in the body and fuel injector sleeves within the bores spaced inwardly from the surface of the bores and extending upward from each lower chamber, whereby coolant flows from each lower chamber to the cross-flow passage and through the cross-flow passage to the coolant outlet. 
     
     
       8. The cylinder head as defined by claim  7  wherein the bores forming the flow channels have a machined surface. 
     
     
       9. The cylinder head as defined by claim  7  wherein the flow channels are located approximately in the center of the lower chambers and the lower chambers have multiple inlets at radially outer locations from the flow channels. 
     
     
       10. A cylinder head for a multi-cylinder engine comprising a body having a lower wall defining a firing deck for each cylinder, the body having an interior space forming a water jacket for cooling the cylinder head, the water jacket having two planes of cooling in the head, lower directed cooling plane above the lower wall for cooling the fire deck and an upper transport plane spaced above the lower directed cooling plane and including a cross-flow passage for directing coolant to a coolant outlet, the water jacket further having a flow channel for each cylinder located in a bore in the body that also contains a fuel injector nozzle sleeve, thereby providing fluid communication between the lower directed cooling plane and the upper transport plane and a coolant inlet for each cylinder into the lower directed cooling plane. 
     
     
       11. The cylinder head as defined by claim  10  wherein for each cylinder the lower directed cooling plane includes a lower chamber immediately above the lower wall for cooling the fire deck. 
     
     
       12. The cylinder head as defined by claim  11  wherein the lower chamber for each cylinder is separated from the lower chambers associated with the other cylinders of the head. 
     
     
       13. The cylinder head as defined by claim  11  wherein the lower chamber for each cylinder is connected to an adjacent lower chamber.